git.distorted.org.uk Git - u/mdw/putty/blob - rlogin.c

   1 #include <windows.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <ctype.h>
   5
   6 #include "putty.h"
   7
   8 #ifndef FALSE
   9 #define FALSE 0
  10 #endif
  11 #ifndef TRUE
  12 #define TRUE 1
  13 #endif
  14
  15 #define RLOGIN_MAX_BACKLOG 4096
  16
  17 static Socket s = NULL;
  18 static int rlogin_bufsize;
  19
  20 static void rlogin_size(void);
  21
  22 static void c_write(char *buf, int len)
  23 {
  24     int backlog = from_backend(0, buf, len);
  25     sk_set_frozen(s, backlog > RLOGIN_MAX_BACKLOG);
  26 }
  27
  28 static int rlogin_closing(Plug plug, char *error_msg, int error_code,
  29                           int calling_back)
  30 {
  31     if (s) {
  32         sk_close(s);
  33         s = NULL;
  34     }
  35     if (error_msg) {
  36         /* A socket error has occurred. */
  37         connection_fatal(error_msg);
  38     }                                  /* Otherwise, the remote side closed the connection normally. */
  39     return 0;
  40 }
  41
  42 static int rlogin_receive(Plug plug, int urgent, char *data, int len)
  43 {
  44     if (urgent == 2) {
  45         char c;
  46
  47         c = *data++;
  48         len--;
  49         if (c == '\x80')
  50             rlogin_size();
  51         /*
  52          * We should flush everything (aka Telnet SYNCH) if we see
  53          * 0x02, and we should turn off and on _local_ flow control
  54          * on 0x10 and 0x20 respectively. I'm not convinced it's
  55          * worth it...
  56          */
  57     } else {
  58         /*
  59          * Main rlogin protocol. This is really simple: the first
  60          * byte is expected to be NULL and is ignored, and the rest
  61          * is printed.
  62          */
  63         static int firstbyte = 1;
  64         if (firstbyte) {
  65             if (data[0] == '\0') {
  66                 data++;
  67                 len--;
  68             }
  69             firstbyte = 0;
  70         }
  71         c_write(data, len);
  72     }
  73     return 1;
  74 }
  75
  76 static void rlogin_sent(Plug plug, int bufsize)
  77 {
  78     rlogin_bufsize = bufsize;
  79 }
  80
  81 /*
  82  * Called to set up the rlogin connection.
  83  *
  84  * Returns an error message, or NULL on success.
  85  *
  86  * Also places the canonical host name into `realhost'. It must be
  87  * freed by the caller.
  88  */
  89 static char *rlogin_init(char *host, int port, char **realhost, int nodelay)
  90 {
  91     static struct plug_function_table fn_table = {
  92         rlogin_closing,
  93         rlogin_receive,
  94         rlogin_sent
  95     }, *fn_table_ptr = &fn_table;
  96
  97     SockAddr addr;
  98     char *err;
  99
 100     /*
 101      * Try to find host.
 102      */
 103     {
 104         char buf[200];
 105         sprintf(buf, "Looking up host \"%.170s\"", host);
 106         logevent(buf);
 107     }
 108     addr = sk_namelookup(host, realhost);
 109     if ((err = sk_addr_error(addr)))
 110         return err;
 111
 112     if (port < 0)
 113         port = 513;                    /* default rlogin port */
 114
 115     /*
 116      * Open socket.
 117      */
 118     {
 119         char buf[200], addrbuf[100];
 120         sk_getaddr(addr, addrbuf, 100);
 121         sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
 122         logevent(buf);
 123     }
 124     s = sk_new(addr, port, 1, 0, nodelay, &fn_table_ptr);
 125     if ((err = sk_socket_error(s)))
 126         return err;
 127
 128     sk_addr_free(addr);
 129
 130     /*
 131      * Send local username, remote username, terminal/speed
 132      */
 133
 134     {
 135         char z = 0;
 136         char *p;
 137         sk_write(s, &z, 1);
 138         sk_write(s, cfg.localusername, strlen(cfg.localusername));
 139         sk_write(s, &z, 1);
 140         sk_write(s, cfg.username, strlen(cfg.username));
 141         sk_write(s, &z, 1);
 142         sk_write(s, cfg.termtype, strlen(cfg.termtype));
 143         sk_write(s, "/", 1);
 144         for (p = cfg.termspeed; isdigit(*p); p++);
 145         sk_write(s, cfg.termspeed, p - cfg.termspeed);
 146         rlogin_bufsize = sk_write(s, &z, 1);
 147     }
 148
 149     return NULL;
 150 }
 151
 152 /*
 153  * Called to send data down the rlogin connection.
 154  */
 155 static int rlogin_send(char *buf, int len)
 156 {
 157     if (s == NULL)
 158         return 0;
 159
 160     rlogin_bufsize = sk_write(s, buf, len);
 161
 162     return rlogin_bufsize;
 163 }
 164
 165 /*
 166  * Called to query the current socket sendability status.
 167  */
 168 static int rlogin_sendbuffer(void)
 169 {
 170     return rlogin_bufsize;
 171 }
 172
 173 /*
 174  * Called to set the size of the window
 175  */
 176 static void rlogin_size(void)
 177 {
 178     char b[12] = { '\xFF', '\xFF', 0x73, 0x73, 0, 0, 0, 0, 0, 0, 0, 0 };
 179
 180     if (s == NULL)
 181         return;
 182
 183     b[6] = cols >> 8;
 184     b[7] = cols & 0xFF;
 185     b[4] = rows >> 8;
 186     b[5] = rows & 0xFF;
 187     rlogin_bufsize = sk_write(s, b, 12);
 188     return;
 189 }
 190
 191 /*
 192  * Send rlogin special codes.
 193  */
 194 static void rlogin_special(Telnet_Special code)
 195 {
 196     /* Do nothing! */
 197     return;
 198 }
 199
 200 static Socket rlogin_socket(void)
 201 {
 202     return s;
 203 }
 204
 205 static int rlogin_sendok(void)
 206 {
 207     return 1;
 208 }
 209
 210 static void rlogin_unthrottle(int backlog)
 211 {
 212     sk_set_frozen(s, backlog > RLOGIN_MAX_BACKLOG);
 213 }
 214
 215 static int rlogin_ldisc(int option)
 216 {
 217     return 0;
 218 }
 219
 220 static int rlogin_exitcode(void)
 221 {
 222     /* If we ever implement RSH, we'll probably need to do this properly */
 223     return 0;
 224 }
 225
 226 Backend rlogin_backend = {
 227     rlogin_init,
 228     rlogin_send,
 229     rlogin_sendbuffer,
 230     rlogin_size,
 231     rlogin_special,
 232     rlogin_socket,
 233     rlogin_exitcode,
 234     rlogin_sendok,
 235     rlogin_ldisc,
 236     rlogin_unthrottle,
 237     1
 238 };